1. Field of the Invention
The present invention relates generally a liquid crystal display (LCD) module, and more particularly to a polarizing sheet with function of color conversion and a LCD equipped with the polarizing sheet.
2. Description of the Related Art
FIG. 1 shows a conventional liquid crystal display (LCD), which includes an upper polarizing sheet 1, a lower polarizing sheet 2, a liquid crystal panel 3 between the upper and lower polarizing sheets 1 and 2, and a backlight module 4 under the lower polarizing sheet 2 to provide the liquid crystal panel 3 light. The light of backlight module 4 travels through the lower polarizing sheet 2 first, and convert to polarizing light. The liquid crystal panel 3 is controlled to twist liquid crystal molecules that controls the polarizing light traveling to the upper polarizing sheet 1 or not to show predetermined images.
The backlight module 4 is preferred to provide white light for color LCD, and the color of light is determined by the light source 4a of the backlight module 4. The common light source 4a for providing white light is light emitting diode (LED), however, the white light LED is expensive that increase the cost of LCD. To overcome the above drawback, some LCDs provide blue light LED and an optical film to convert blue light to white light. Although the blue light LED is cheaper than the white light LED, but the optical film increases the thickness of the back light module and the cost.